There have been two very minor updates since the Windows Phone version of WhatsApp received the revamp treatment, and neither of these updates saw fit to include a changelog. Thus we can only assume at this point that the updates were very minor.
More than likely, both version 2.10.506 and version 2.10.523 updated the internal code itself, making it more efficient for the developers. It may also include minor bug fixes and a few tweaks here an there to make the app run a bit more smoothly. Again, though, without a changelog attached, we can only speculate.
It’s obvious, though that the WhatsApp team has been very supportive of and has put a great amount of work into its Windows Phone effort and we certainly can’t fault them for that at all. After all, the less bugs we have to deal with, the more time we can spend Whatsapping our friends.
If you haven’t already, you can pick up this minor update in the Windows Phone Store.